When Heroes defeat aliens, they gain one Experience Point for each defeated Alien Model. When a Hero has 5 Experience Points, it can level up its abilities from Level 0 to Level 1, and when it gains another 7 Experience Points (for a total of 12), it levels up from Level 1 to Level 2.
Hero
The term Hero refers to each of the characters played by the Hero Players. Each Hero has a Model and two boards: one Hero Profile Board (sometimes called Hero Profile Card) and one Hero Dials Board.
The Hero Profile Board contains the name, portrait, equipment icons and ability descriptions for the Hero, and also has a few areas where equipment, tokens and other stuff belonging to the Hero is placed. The abilities are described in three levels: the starter level, Level 1, and Level 2. Heroes go up to Level 1 when they have gained 5 Experience Points, and to Level 2 when the have gained another 7 Experience Points (meaning a total of 12).
The Hero Dials Board contains various numeric stats for the Hero; there are five such stats: Melee Value, Shoot Value, Health, Defence Value and Move Value. The Hero Dials Board, as the name suggests, contains dials that can be turned, changing some of the Hero's stats. However, only three of the stats change, while two remain fixed, and it varies between different Heroes which the two fixed stats are. However, the Health stat is variable for all Heros.